Daniel Ricciardo says Sunday's Chinese Grand Prix victory alone is not enough to convince him to stay at Red Bull next season.
Ricciardo's current contract is up at the end of the season and for the first time in his career he will be free to explore options at other teams without Red Bull having the ultimate say over his next move. He went into this year's championship hoping to challenge for the title but has made no secret of his desire to keep his options open for 2019 if Red Bull fails to perform.
His victory at last weekend's Chinese Grand Prix propelled Ricciardo to fourth in the drivers' standings, 17 points adrift of championship leader Sebastian Vettel, but after a series of reliability issues in the opening two races he says there is more to do to convince him to stay at Red Bull in 2019.
"I definitely want to be with the best car," he told Australia's Channel 10. "I think the weekend proved that if I've got the opportunity to win I can pull it off. I can handle that pressure and that intensity.
"If we can win a few more with Red Bull now then that looks very attractive. If not, then I guess there are probably other options.
"Obviously the win helps but if we were finishing sixth every race this year, then that's not the most attractive option to me."
Red Bull has been third quickest behind Ferrari and Mercedes in qualifying so far this year and Ricciardo is still not convinced his team has the outright pace to challenge for the title.
"I think it's still too early to say yes. We won at the weekend but we need to win regularly to kind of show that. If we come out and win again in two weeks in Baku then I'll probably say yes."
If Ricciardo decided to leave Red Bull it would most likely be for either Mercedes or Ferrari. In recent weeks he has been linked with a move to the Italian team, but Red Bull boss Christian Horner doubts Ricciardo would want to play second fiddle to his former teammate Sebastian Vettel.
Ferrari's current second driver Kimi Raikkonen has regularly been forced to play a supporting role to Vettel -- including at the Chinese Grand Prix where his pit stop was delayed to try to help Vettel pass Valtteri Bottas for the lead -- and Horner says Ricciardo would not fit that mould.
"If you look at Kimi's race [in China], I didn't understand that strategy. I think Daniel's happy in the environment he's in. If we can give him a car like we did today, why would he want to be anywhere else?
"The win was great for him. He had the energy store failure in Bahrain, he had a turbo failure here in final practice, losing him important track time. You get to a point where you think 'what next?' But it's a great confidence booster for him, to get this result now in this point in the year. Everything is wide open."